Telechelic polystyrene with both perfluoroalkyl (Rf) and coumarin groups (CouRf-PS-CouRf) was precisely synthesized by a living anionic polymerization and a quantitative end-functionalization. Then thin polymer films was applied for the UV-irradiated photodimerization of the coumarin groups in order to fix Rf groups at to lead the excellent hydro and oleophobic film surface property. The polymer chain mobility at the film surface was well controlled by reversible photodimerization of coumarin groups with different UV wavelengths. On the other hand, coumarin-functionalized polystyrene without Rf groups (Cou-PS-Cou) showed the low photodimerization reactivity and the poor oleophobicity. As a result, surface concentrated Rf groups enhanced the photodimerization reactivity of coumarin groups at the film surface.